The Influence of Laboratory Experience Timing on
Student Knowledge-Level Achievement in an
Undergraduate Introductory Agricultural
Mechanics Course
Andrew J. Baker1
Western Illinois University
Macomb, IL 61455
NACTA
Andrew C. Thoron2 and Brian E. Myers3
University of Florida
Gainesville, FL 32611
Thomas J. Cody4
Western Illinois University
Macomb, IL 61455
Abstract
Instructors often reflect upon their teaching
techniques as they begin the process of constructing a
course that contains both a lecture component and a
laboratory experience. Often instructors are placed
in a situation, due to limited resources, where
laboratory activities can not coincide directly with
the lecture portion of the course both in time and
subject matter. Recognizing the laboratory as a time
where students can apply the content knowledge
presented in lecture to influence retention of information it is important to give each student the best
experience possible. Noting the importance of the
laboratory portion of agricultural mechanics and
having limited space, equipment, and financial
resources, instructors must create methods to
maximize the educational impact of the laboratory
experience and serve student learning. Students
were grouped by prior experience in content area as
well as students having completed or not completed a
laboratory activity related to the lecture material at
the time the lecture exam was given. Test scores were
analyzed in an introductory agricultural mechanics
course to evaluate possible group differences.
Findings indicated no significant differences on
content knowledge test scores between students who
possessed prior experience versus those students who
did not possess prior experience in the subject of
small engines. Timing of the laboratory activity was
found to have no bearing on how well students
performed on the content knowledge assessment.
Introduction
According to America's Lab Report (National
Research Council [NRC], 2006) the need and the role
of the laboratory instruction has increased in the past
20 years. Driver (1995) states teacher's interventions,
expectations, and actions help promote further
student understanding in the laboratory setting.
Quality laboratory instruction thus becomes a
valuable concept in the curricula. The National
Research Council (2001) states due to this growing
awareness many institutions (secondary and
postsecondary) have improved laboratory facilities.
Smith et al. (2002) find facilities a serious problem for
laboratory instruction. Developing methods which
promote student learning and lab utilization is a key
factor to maintaining current facilities and allowing
for administration to develop new or modernize
current structures (NRC, 2006).
The state of laboratory facilities and of resources
to operate those facilities is of great concern in many
secondary and post-secondary educational settings.
In many cases, institutions have capital funds to
build laboratory facilities, yet fail to adequately fund
the equipment and supply needs of those facilities
either due to lack of operational funds or poor
administrative budgeting (NRC, 2006). Banilower et
al. (2004) reported that there is great disparity in
funding for laboratory facilities and supplies based on
institution size and demographic composition of the
students.
America's Lab Report (NRC, 2006) outlines seven
goals of laboratory experiences: (1) enhance content
knowledge mastery, (2) develop scientific reasoning
skills, (3) develop an understanding of the complexity
and ambiguity of empirical work, (4) develop practical skills, (5) understand the nature of science, (6)
cultivate interest in science and interest in learning
science, and (7) develop teamwork abilities.
Ultimately, the goal is to move the learners' understanding from the lower levels of Bloom's Taxonomy
1
1University Circle, B21 Knoblauch Hall; Tel: 309-298-1246; Fax: 309-298-2280; Email: AJ-Baker@wiu.edu
310 Rolfs Hall, PO Box 110540; Tel: 352-392-0502 Ext. 238; Fax: 352-392-9585; Email: athoron@ufl.edu
3
308 Rolfs Hall, PO Box 110540; Tel: 352-392-0502 Ext. 236; Fax: 352-392-9585; Email: bmyers@ufl.edu
4
1University Circle, 115N Horriban Hall, Tel: 309-298-1229; Email: TJ-Cody@wiu.edu
2
6
NACTA Journal • March 2008
(Bloom et al., 1956) to the higher levels. However, in
order to reach those higher levels, a solid foundation
must be laid at the knowledge level upon which
further understanding can be built (Anderson and
Krathwohl, 2001). Hofstein and Lunetta (2004) note
there is little research which investigates when
laboratory experience ought to occur in coordination
with classroom lecture. The question if laboratory
instruction should precede, coincide with, or follow
classroom instruction remains unanswered.
Compounding the pedagogical issue and implications
of the timing of laboratory instruction is the more
practical issue of educational laboratory facilities and
supplies.
Regardless of the logistical and resource challenges of managing laboratory instruction, providing
quality laboratory experiences for learners is still
important (NRC, 2006). Allowing students to troubleshoot problems and develop further knowledge and
understanding through investigation brings Blooms
taxonomy to the synthesis and evaluation levels
(Bloom et al., 1956). Diederen et al. (2006) state
laboratory skills are regarded as indispensable for
learning objectives and application of the reality of
phenomena. “Laboratory skills cannot (or hardly) be
learned outside the laboratory” (Diederen et al.,
2006, p. 230). The key then to providing this important educational experience lies in the practitioner's
ability to creatively balance the ideal with the
practical.
Situation
In this particular situation, the class had more
students than supplies. Eight small engines were
available for use with all sections of agricultural
mechanics. The instructor would lecture over small
engine topics and one laboratory section would focus
laboratory instruction on small engines. Meanwhile,
other sections would be applying knowledge from
topics previously discussed in class or yet to be
discussed in class (electricity, construction, and
surveying). Laboratory sections would be placed on a
weekly rotation throughout the semester to ensure
completion of all required laboratory activities. It is
noteworthy that all laboratory activities were
directly linked with lecture principles, but were
separated by time, resources, and facilities.
The instructor at this Midwestern public university used this method for six years and was challenged
each year by students who were not receiving the
laboratory preparation at the time of lecture.
Students perceived they were scoring lower on their
knowledge level assessment than peers who were
receiving the laboratory component in synchronization with lecture. This created a dilemma for the
instructor as he believed students held no advantage
due to the laboratory experience while being assessed
on mechanical principles. Although maybe ideal, the
instructor was unable to effectively provide the same
laboratory experience for each laboratory section due
NACTA Journal • March 2008
to unavailable equipment, limited resources, and
course time restraints. This limitation led to staggering topical laboratory investigations over all concepts
taught during the 16-week semester. This instruction
strategy was selected since the instructor did not
want to compromise individual learning and create
larger laboratory groups thus lowering the amount of
hands-on experience for students.
Content knowledge taught in the classroom
supplemented the laboratory experience that
provided for investigation and analysis of skills.
Students were assessed on classroom mechanical
principles and laboratory experiences; making it
possible to teach and assess content knowledge
through classroom tests and assess laboratory
through modules. Each student had access to course
notes, PowerPoint slides, video clips, and a database
of websites for further investigation through
WebCT®. The lecture portion of the course was
utilized to enforce the course notes through related
class discussions and websites. The laboratory
activities were directly related to course content and
development of mechanical attributes.
Each student enrolled in the course had the same
instructor for the lecture and laboratory portions of
the course. The primary instructor and several lab
assistants supervised all laboratory activities. The
instructor took into consideration how he could
provide students with information so they were not at
an academic disadvantage by not having laboratory
experience on a knowledge level exam; this led to the
assessment of this type of instructional methodology.
Instructional strategies were evaluated in an
introductory agricultural mechanics course. The
course is a lecture-laboratory course designed to
provide basic instruction on principles in small gas
engines, electricity, construction, and surveying.
Students receive two hours of classroom based
lecture-discussion and two hours of laboratory
experience each week.
Purpose and Objectives
The purpose of this study was to determine the
influence of the timing of laboratory experiences has
on student content knowledge-level achievement in
an introductory agricultural mechanics course. The
objectives of the study were as follows:
1. To determine the influence of previous experience on student content knowledge-level achievement.
2. To determine the influence of laboratory experiences on student content knowledge-level achievement.
Since the research base does not support the use
of directional hypotheses, null hypotheses were used
to analyze these objectives. All null hypotheses were
tested at the .05 level of significance.
Ho1: There is no significant difference in student
content knowledge-level achievement of students
based upon previous experience.
HO2: There is no significant difference in student
7
The Influence
content knowledge-level achievement of students
based upon completion of a laboratory exercise.
Methods
This study utilized a static-group design (Campbell and Stanley, 1963), since random assignment of
subjects to treatment groups was not possible. Intact
groups were used and treatments were randomly
assigned to groups. The two treatments used were:
(1) subject matter instruction in a lecture-discussion
setting coinciding with laboratory instruction and (2)
subject matter instruction only in a lecturediscussion setting with no laboratory activities prior
to the lecture exam.
The target population for this study was students
enrolled in a state university during the spring 2006
semester. The accessible sample consisted of an intact
group of students enrolled in an introductory agricultural mechanics course (n = 69). All of the students
were enrolled in the same lecture section, but then
had the option to enroll in two separate laboratory
sections. Usable data were obtained from all students
in the sample. As a clinical study, the findings of this
research are not generalizable beyond the sample.
Data were gathered by
instructor developed
instruments following the
completion of a small
engines unit of instruction.
Content knowledge-level
achievement was measured
by assessment derived from
the knowledge-level
objectives of the course.
Demographic data were
collected via a written
questionnaire.
ing the test scores of male and female student
produced a t-value of 0.674 (P = .503).
Objective one of this study sought to determine
the influence of previous experience with mechanics
on a knowledge level assessment. Students selfreported any prior experience with small gas engines
prior to data collection. Thirty students indicated
mechanics experience prior to entering the university
course. It can also be noted that all students who
indicated prior experience were male. Therefore, no
analysis was completed investigating the influence of
prior experience within gender. The null hypothesis
of no differences in the knowledge level lecture based
assessment based upon previous experience was used
to assess this influence. An independent t test
produced a t-value of 1.773 (P = .081). Therefore, the
null hypothesis of no difference in the knowledge
level assessment of students based upon previous
experience failed to be rejected (see Table 2).
Objective two sought to determine the influence
of having a laboratory experience on a knowledge
level assessment. The null hypothesis of no differences in the knowledge level classroom based assessment based upon laboratory experience was tested.
Results
The population of this study included the 69
undergraduate students enrolled in the introduction
to agricultural mechanics course. The first laboratory
section which received laboratory instruction on
dissembling and reassembling a small gas engine
coinciding with lecture content included 34 students.
Twenty-nine percent (n=10) of the students in
section one were female. The second laboratory
section, which did not receive laboratory instruction
prior to the lecture exam, included 35 students of
which 17% (n=6) were female.
Upon further investigation, no significant
difference was found in final test scores based on
gender (see Table 1). An independent t test compar-
8
An independent t test comparing the test scores of
students who had received laboratory instruction
with those student who had received only classroom
(lecture) instruction revealed a t-value of .147 (P =
.883). Therefore, the null hypothesis of no difference
in the knowledge level assessment of students based
upon receiving laboratory experience failed to be
rejected (see Table 3).
Discussion/Implication
The question of how a lecture/laboratory course
should be structured, especially with large course
enrollments, is one faced by many in our profession.
Should laboratory activities be directly coordinated
with lecture content at the
specific time the content is
being addressed in lecture?
The literature tells us that
integrating laboratory
instruction and lecture
NACTA Journal • March 2008
The Influence
instruction is the ideal (NRC, 2006). However, in
many cases due to limited resources instructors are
not able to live in this “best case scenario.” The
challenge then becomes one of finding the means to
accomplish the educational objectives of the instruction within the resource constraints.
One possible means to accomplish this would be
to increase laboratory group size. However, this could
reduce the amount of contact time an individual
student has with the phenomenon under investigation. This study investigated the innovation of
instituting a rotational schedule of laboratory
investigation to maximize the use of limited laboratory space, equipment, and supplies.
No significant difference in knowledge level
achievement was discovered based on student prior
mechanics experience or when the laboratory
experience occurred. Therefore, students who
completed the lecture based exam prior to completing
the laboratory exercises were not at an academic
disadvantage compared to their counterparts who
had completed the laboratory portion of the unit of
instruction.
These findings in no way diminish the importance or role of laboratory instruction. Rather,
according to the results of this study, instructors can
vary laboratory activities with lecture content as long
as they are assessed separately. Laboratory activities
should still be utilized to allow students to practice or
apply their newfound knowledge in a supervised
environment with the goal of achieving the higher
levels of Bloom's Taxonomy. Further research is
needed to determine the influence of when the
laboratory experience occurs on achievement of the
higher levels of Bloom's Taxonomy.
As Diederen et al. (2006) stated, laboratory
instruction is a critical tool in increasing a student's
understanding and ability to apply knowledge.
However, the reality of disparity in laboratory
facilities and equipment noted by Banilower et al.
(2004) often requires instructors to be creative in how
laboratory instruction is delivered.
NACTA Journal • March 2008
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